The invention described herein may be manufactured and/or used by or for the Government for governmental purposes without the payment of any royalty thereon.
In the design of some artillery weapons, the tipping parts, i.e., those parts that pivot in elevation and depression, are located forward of the trunnions with the result being that the center of mass of the tipping parts are considerably forward of the pivot point or trunnion throughout the gun tube range of elevation.
The positioning of these parts also produces a shifting of the center of mass of the tipping parts throughout the gun elevation positions and predominately throughout the lower range of degrees of elevation. The inequality and shifting in the center of mass imposes a depressing effect on the tipping parts which presents a problem of weapon accuracy. This shifting also results in undue strain correction requirements being imposed on the gun elevating mechanism, such as a servomotor, when located near the trunnions and, consequently, variations in the load requirements imposed on the tipping parts elevating mechanism, whether manually or by power means.
In the prior art, spring equilibrators have been employed in attempts to exert a compensating or counterbalancing force on the tipping parts. Idealistically the force exerted by the equilibrators should be equal and opposite to that produced by the varying unbalanced gravity load imposed on the tipping parts at each degree of elevation in its range of elevations so that thereby the servomotor or manual load requirements will be constant and minimized. The counterbalancing forces of the spring equilibrator are functions of the spring forces and equilibrator kinematics. The supply response curve can be made exactly equal to the demand curve by adjusting the equilibrator kinematics, however design considerations preclude this in some systems.
Thus, the prior art spring actuated equilibrator assemblies relied heavily on the kinematics of the equilibrators for balancing. This new equilibration configuration allows for balancing of the demand response by varying the properties of a set of springs rather than the kinematics of the equilibrator.